Adjustable spring mount and shock absorber assembly for tractor seats or the like



June 1954 A. R. HEMPE, JR

ADJUSTABLE SPRING MOUNT AND ASSEMBLY FOR TRACTOR SEATS Filed Dec.

Evy/swim? Arthur R. Hem 2e :77? M w@% %5 Patented June 8, 1954 2,680,472 ADJUSTApLE SPRING MOUNT AND snoc ABSORBER ASSEMBLY FOR "TRACTOR SEATWKTFIELIK Ar hu R- H e e J ne il a n-r 9 Houdaille H rshey Corporation, netr n; Mich; amt a iqg of Mi n Application December 9, 1950, Serial No 200,062

0 0 1 5-7 1 The present invention relates to improvements able fashion a raoket Ill pivotal y ec red as by n. t e mo nti of e bucket-ty e. rlike seats means ofa be t or pm. I! to ach ent plate such as are used on tractors and like equipment, or bracket 12 secured as by means of bolts lg to may be used on tractor and other outdoor rolling may be used, are usually operated over. rough machines or the like. such as a unit 51 including a coiled compression Another object of the invention is to provide spring l8 and a shock absorber I9 is provided bea seat cushioning assembly of the kind utilizing tween the underside of the seat and the undera coiled compression spring and a direct-acting 15 lying portion of the vehicle. 'The shock absorber ous Weights of riders on the seat. with a va v s arrangement enabling slow rel A further object of the invention is to provide tive reciprocal movements of the piston and cyl- Other objects, features and advantages or the is not therefore deemed necessary to enlarge herethe following detailed description of certain preabsorber.

ferred embodiments thereof taken in con unction For mounting the shock absorber L9, its lower with the accompanying drawing, in which end is equipped with an eye knuckle member 20 Figure 1 1s a side elevational view of a bucketwhich is secured as by means of a bolt 2| to a type seat having a cushioning and shock absorbinvention; l 5.

ure 2 is a fragmentary enlarged verticalsec- At its upper end, the shock absorber I9 has a i n l Vi w, partially in Side elevat on, of the piston rod '24 projecting relatively reciprocably a bracket-2'8 whiehin turnis'seciire'd to the underside of the seat arm head '8. The construe? Y. e. tion and relationship hasten thaf'the ho Shock absorbmg absorber is installed ona'do'wnyvardand forv rd A -W1 1 5 Qf1 h 1iP w t Whig}??? slant inore orle's'sconform'ing the are" of We present mventwn i cenq rnes an isome -r s a ment' of the' s'at taste sitings'uie and seen in pressed metal st u e e eated 1.1 411? a r eted service; level m 1 wh lant downwardl a d f The coiled compression spring Wardly and has upper e, ra y hori on what iargerinternei diameter'tha h agiportm ,5 t Wish th seat-:5 ssecnred as by diameter'of the shockabsorber l9 means of one or more bolts {it its lowerend concentrically about the shock portion the arm :1 has attached thereto in a suitmanner toise'rve as a cushioning seat 5. For this purpose, the lower end of the spring I8 is seated on a seating flange 29 preferably mounted on the lower shock absorber knuckle eye 26. At its upper end, the spring i8 is engaged by thrust cap or seating structure 33 carried by the upper end portion of the piston rod 24. Thereby, the weight of a person sitting in the seat is thrust upon the spring is and as the vehicle with which the seat is associated moves over unevennesses in the path of the vehicle, the seat can move up and down due to the resilient yieldability of the spring l8. Over-rapid and sudden compressions of the spring l8 are resisted by action of the shock absorber 18. Rebound is snubbed by the shock absorber l9.

However, in order to attain highest efficiency in operation of the shock absorber 19, the projected or extended relationship of the piston rod 24 relative to casing, and thereby the position of the piston within the cylinder in service with a person sitting in the seat 5 should be predetermined as a midway position so that there will be approximately equal compression and rebound movement permitted within the range of relative reciprocal movement of the cylinder and piston of the shock absorber. Since the weight of the person sitting in the seat 5 determines the dead weight compression of the spring 13, a weight of spring that will provide a mid point relationship of the cylinder and piston for a given dead weight, and thus a comfortable ride for a person of such weight, will be thrown out of balance when the seat is used by a person whose weight diiiers substantially from the weight. When thus out of operative balance, the riding characteristics at one end of the operative range of the shock absorber i9 deteriorates in proportion as the users weight deviates from the mean weight. For example, when a person heavier than the mean weight uses the seat 5, the compression portion of the operative range of the shock absorber I9 is shortened by the greater compression of the spring 18 and thereby the compression strokes of the piston within the shock absorber may terminate abruptly and jarringly or with a jolt under severe compression. On the other hand, when a person of substantially lighter weight than the mean weight for which the spring extension of the piston rod 24 in service may prevail that the rebound portion of the operative range of the piston is shortened to such an extent that on severe rebound inadequate range is provided in the shock absorber and a jolting or jarring termination of the rebound stroke under severe conditions may occur.

According to the present invention means are provided for effecting adjustment in the relative overall length of the spring 18 and the shock absorber 19 so as to compensate for variations from a rated mean loading relationship of the spring and shock absorber. In a simple and efficient arrangement, the upper end thrust cap structure 38 of the assembly is constructed to enable the relative spring and shock absorber adjustment. Hence, the thrust structure comprises an elongated inverted cup-like member 3i having the base or web portion thereof centrally apertured as at 32 and engaged about a reduced diameter portion 33 at the upper extremity of the piston rod 24, the assembly of the piston rod, the knuckle eye and the. cap member 3i being secured rigidly as by means of welding 34.

The cap member 3| has an elongated cylindrimean or predetermined I8 is rated uses the seat, such for example at cal wall portion 35 which is internally of somewhat larger diameter than the external diameter of the shock absorber casing and is externally of somewhat smaller diameter than the internal diameter of the spring it so that the cylindrical wall portion 35 will in service fit freely and out of contact between the shock absorber casing and the spring. Externally the cylindrical wall or flange portion 35 is threaded and is threadedly engaged by an abutment annulus or flange 31 of angular cross section providing an abutment shoulder 38 against which the upper end of the spring is thrusts. By adjustably threading the thrust shoulder flange member 31 longitudinally of the cylinder 35, relative adjustment of the length of the spring is and the extended or operative condition of the shock absorber is attained. Thus, assuming that the spring I8 is rated for a normal dead weight of lbs. in the seat 5, a mid way adjustment of the thrust shoulder flange 3'! on the cylinder 35 will attain the proper balanced condition of the shock absorber under dead weight of 150 lbs. If a person substantially lighter than 150 lbs. is to use the seat 5, then the thrust shoulder flange 31 is turned u toward the upper end of the cylinder 35 because the spring I8 is compressed less under the dead load of the lighter person and thereby the piston rod 24 is retracted less from the unload protracted position thereof when the load of the lighter person is imposed on the assembly. On the contrary, when a person substantially heavier than the mean rated load of 150 lbs. is to use the seat 5, the thrust shoulder flange 31 is turned down on the cylinder 35 toward the lower end in proportion to the deviation in weight of the user of the seat, so as to compensate for the greater dead load compression of the spring is under the weight of the heavier person and thereby assure that the piston rod 24 will be retracted from a greater protracted distance to substantially the balanced condition desired of the piston within the cylinder of the shock absorber under the dead load of the heavier person.

To facilitate turning the threadedly on the cylinder 35, it may be provided with a hub 39 equipped with any desired wrench engagement means such as a series of radial sockets 40 to receive a spanner wrench.

Adjusted positions of the thrust flange member 3'! are maintained by suitable means such as a lock nut 4| threaded onto the cylinder 35 for locking engagement with the upper end of the hub 39 and desirably equipped for engagement by the same wrench that is adapted to manipulate the shoulder flange member 31, such as a spanner wrench and for this purpose may be equipped with spanner wrench radial sockets 42.

Instead of having the relative spring lengthening adjustment means at the top of the cushioning and shock absorber unit H, such adjustment means may be provided at the bottom of the unit, as shown in Fig. 3. For this purpose, the lower spring thrust or abutment member 29 as shown in Fig. 1, may be replaced by an adjustment structure 30 which operates substantially like the adjustment structure 38 described in connection with Figs. 1 and 2 but is adapted for the bottom of the unit instead of the top of the unit. To this end, the lower adjustment unit 38' comprises an externally threaded cylinder member 43 carried by the lower knuckle eye 20 of the shock absorber structure and freely encircling the lower end portion of the shock absorber casing and freely received within the lower end shoulder member 37 v portion of the storing it}. Threaded oh the cylinder member 43 is a thrust shoulder flange 44 of angular cross section against which the lower end of the spring seats. A locknut 45 bears against the lower end oi the hub portion of the thrust shoulder flange 4i ta lock the latter in shock absorber if! for any weight of rider within a substantial range of weights.

For the usual anticipated service requirements, the adjustment means for the cushioning-shock from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In combination in apparatus of the charof the spring, means carried by the upper end of the shock absorber providing an abutment for one of said abutment thrust flange annulus threaded on said cylinder and threadedly adjustable longitudinally thereof to vary the relative length of the spring and shock absorber for service conditions.

3. In combination in cured fixedly to the upper end portion of the piston rod.

8. In combination in a vehicle seat installation, a seat, means supporting the seat for up and down connecting one of said members to said seat. cated at the end of the spring adjacent said fixed second means connecting the other of said memsupport. bers to a fixed support, and an abutment associated with each of said first and second means Y R fefences cited in t fil of t te for maintaining said spring therebetween, one of 5 4 said abutments being adjustable along the shock UNITED STATES PATENTS absorber to vary the unloaded protraction of the Number Name v Date piston rod member from the cylindrical body 874,721 Adams Dec. 24, 1907 member to compensate for persons of differing 2,534,047 McIntyre Dec. 12, 1950 weights using the seat. 10 2,558,928 Bryan July 3, 1951 9. A vehicle seat installation as defined in claim 8, wherein the adjustable abutment is located at FOREIGN PATENTS the end of the spring adjacent said seat. Number Country t 10. A vehicle seat installation as defined in 1 4,532 Germany 15, 90

claim 8 wherein the adjustable abutment is 10- 15 

